Loose leaf binder



July 26, 1932. J, C, DAWSON 1,868,793 LOOSE LEAF BINDR Filed Feb. 28,1951 v gigs 16 instance,

Patented July 26, 1932 UNTED STATES PATENT OFFICE JAMES C. DAWSON, OFVJEBSTER'GROVES, MISSOURI,.ASSIGNOR TO ELMA N. DAWSON,

OF WEBSTER GROVES, MISSOURI LOOSE LEAF BINDER Application filed Februaryv28, 1931. Serial No.'519,134.

This invention relates to loose leaf binders and has for its objects toprovide means to assemble loose leaf binders of the spring cover type tobook backs; to provide sim- 5 ple means for holding booster levers onbinders of such a type; and to secure the closing of the end pairs ofpaper-holding prongs with a pressure which equals or exceeds thatclosing the intermediate pairs.

In binders of the spring cover type, it has been customary to rivet thebinder mechanism to the book back. It is, however, preferable to havethe binder detachably connected to the book back for in ythe latter therequirements of the trade can be met with fewer type of covers andbinder mechanisms.

These and other objects and advantages of the invention will becomeapparent from 20 the specication and the appended drawing,

in which Fig. 1 represents a loose leaf binder shown in perspective;

Fig. 2 is a longitudinal, vertical section of a portion of the binderillustrated in Fig. 1;

Fig. 3 is a bottom plan view of that portion of the binder illustratedin Fig. 2;

Fig. 4 is a vertical, transverse section of the binder mechanism on theline 4-4 of Fig. 2;

Fig. 5 illustrates the method of assembly of the spring cover plate tothe binder mechanism; and

Fig. 6 is a perspective view showing in detail the booster lever, thespring clip and a portion of the toggle plates.

Loose l-eaf binders of the type illustrated in Fig. 1 comprise twoarticulated toggle plates 11 and 12, bearing the paper-holding prongs 13and 14 arranged to mate with the opposing prongs. A spring cover plate15 engages the toggle plates along their outer margins and appliespressure in such a way that a dead center mechanism is formed whicheither `forces the prongs into engagement or holds them apart.

I attach the binder to the book back by providing small reliefs 16, 16cut in the outer edges of the toggle plates near each close of theirends and hookingfthe curved margins of a clip 18 over the plates atthese points. The clip is curved to fit the book back 19 and bearsanaperture 21 through which a loop 22 struck up from the back projectsand over'which a key 23 is 'thrust to lock the binder to the back..

`Thebooster lever 124, a type more particularly disclosed in a companionapphcation, comprises a thumb arm'25, `a vertical arm A26, and atoggle-operating arm 27. As indicatedin the figures, two slots 28, 28are cut into the vertical arm 26 which'are initially engaged by thebevelled nose 29 of a latch` 31A forming a terminal extension upon eachof the toggle plates.

The assembly of thedevice is as follows: The clips 18,18 are sprung overthe toggle plates 11 and 12 sojthat rtheir hooked margins 17 engage therelieved portions 16, 16. The articulating buttons 32, 32 hold theplates in proper position. The booster lever is then placed so that thebevelled nose 29 of the latches 31 engage the slots 28 and the arm 27extends beneath the toggle plates, as indicated in Fig. 4. When the endofthe thumb arm 25` is pressed inwardly, the

plates are forced apart against the pressure of thespring clip 18 and,asthe latchespass the arm 26, the plates spring back into place and holdthe booster lever permanently in position. v l

- The-spring cover plate is next applied. as

is indicated in Fig. 5,' by rst forming it in v se p the spring plate18. Then the key 23 is thrust under the loop and over the clip.

The common diiiiculty with loose leaf binders is the fact that thespring which closes the prongs may really be considered ascomprisingthree springs, that tending to the Central pair beingsubstantially engaging the outer edges of longer and consequently muchmore powerful than that tending to close the outermost pairs of prongs.Sometimes, the prongs do not close at all but gape apart slightly andfrequently the ends catch in the paper leaves and tear them as the pagesare turned.

Since the clip 1S is a spring section, its strength is added to that ofthe spring cover l5 and, therefore, the end pairs of prongs may be madeto close with a pressure equal to or in excess of that tending to closethe central pair of prongs.

Although, as I have explained, a spring clip has particular advantages,in so far as attachingthe book is concerned, the clips 18 may berelatively rigid, and in that case the distance between the hookedmargins 17 is as great as the length of the straightened toggle. Theslight looseness that results is hardly noticeable in handling the book.

'Vhat l claim, therefore, is:

l. A loose leaf binder having a pair of articulated toggle platesbearing a plurality of paper-holding prongs arranged in mating pairs, anarched spring` cover plate engaging the outer edges of the toggle platesand normally urging the prongs into engagement` and means including aspring clip extending beneath the toggle plates to cause the end pairsof prongs to close with a pressure at least as great as that tending tocause the engagement of those intermediately placed.

2. A loose leaf binder having al spring cover plate provided with hookedmargins, a pair of articulated prong-holding toggle plates having theirouter edges engaged by such hooked margins, a back, and means to c holdthe binder assembled to the back including an arched clip engaging thetoggle plates and extei'iding beneath them, and means to lock the clipto the back.

3. A loose leaf binder having a pair of articulated toggle platesbearing paperholding prongs, a portion of the outer edge of each platebeing recessed adjacent each of its ends, an arched clip having hookedmargins engaging the recessed portion of the edge and extending beneaththe plates and provided with means whereby the binder may be attached tothe back, and a spring cover plate having hooked margins engaging thetoggle plates upon their outer edge.

A loose leaf binder having a pair of articulated toggle plates providedwith paper-holding prongs and having a recessed portion upon the outeredge of each plate, a spring cover plate having hooked margins thetoggle plates, a clip having hooked margins engaging the recessedportion of the plates and extending beneath them, a back, a loop uponthe back, an aperture in the clip adapted to engage the loop, and a keyeX- tending over the clip and under the loop for holding the binderassembled to the back.

5. A loose leaf binder having a pair of articulated toggle platesbearing a plurality of paper-holding prongs arranged in mating pairs, anarched spring cover plate engaging the outer edges of the toggle platesand normally urging the prongs into cngagement, and means to cause theend pairs of prongs to close with a pressure at least as great as thattending to cause the engagement of those intermediately placed, whichcomprises a short arched spring section located adjacent to each end ofthe plates and provided with hooked margins engaging the outer edges ofthe toggle plates.

In testimony whereof I atlix my ture.

signa- JAMES C. DAVSON.

